162 research outputs found
Enhanced Integrated Scoring for Cleaning Dirty Texts
An increasing number of approaches for ontology engineering from text are
gearing towards the use of online sources such as company intranet and the
World Wide Web. Despite such rise, not much work can be found in aspects of
preprocessing and cleaning dirty texts from online sources. This paper presents
an enhancement of an Integrated Scoring for Spelling error correction,
Abbreviation expansion and Case restoration (ISSAC). ISSAC is implemented as
part of a text preprocessing phase in an ontology engineering system. New
evaluations performed on the enhanced ISSAC using 700 chat records reveal an
improved accuracy of 98% as compared to 96.5% and 71% based on the use of only
basic ISSAC and of Aspell, respectively.Comment: More information is available at
http://explorer.csse.uwa.edu.au/reference
Normalization of noisy texts in Malaysian online reviews
The process of gathering useful information from online messages has increased as more and more people use the Internet and other online applications such as Facebook and Twitter to
communicate with each other.One of the problems in processing online messages is the high number of noisy texts that exist in these messages.Few studies have shown that the noisy texts decreased the result of text mining activities.On the other hand, very few works have investigated on the patterns of noisy texts that are created by Malaysians.In this study, a common noisy
terms list and an artificial abbreviations list were created using specific rules and were utilized to select candidates of correct words for a noisy term.Later, the correct term was selected
based on a bi-gram words index.The experiments used online messages that were created by the Malaysians.The result shows that normalization of noisy texts using artificial abbreviations list
compliments the use of common noisy texts list
Schema Normalization for Improving Schema Matching
Schema matching is the problem of finding relationships among concepts across heterogeneous data sources (heterogeneous in format and in structure). Starting from the \hidden meaning" associated to schema labels (i.e. class/attribute names) it is possible to discover relationships among the elements of different schemata. Lexical annotation (i.e. annotation w.r.t. a thesaurus/lexical resource) helps in associating a \u201cmeaning" to schema labels. However, accuracy of semi-automatic lexical annotation methods on real-world schemata suffers from the abundance of non-dictionary words such as compound nouns and word abbreviations.In this work, we address this problem by proposing a method to perform schema labels normalization which increases the number of comparable labels. Unlike other solutions, the method semi-automatically expands abbreviations and annotates compound terms, without a minimal manual effort. We empirically prove that our normalization method helps in the identification of similarities among schema elements of different data sources, thus improving schema matching accuracy
Schema Label Normalization for Improving Schema Matching
Schema matching is the problem of finding relationships among concepts across heterogeneous data sources that are heterogeneous in format and in structure. Starting from the \u201chidden meaning\u201d associated with schema labels (i.e. class/attribute names) it is possible to discover relationships among the elements of different schemata. Lexical annotation (i.e. annotation w.r.t. a thesaurus/lexical resource) helps in associating a \u201cmeaning\u201d to schema labels.However, the performance of semi-automatic lexical annotation methods on real-world schemata suffers from the abundance of non-dictionary words such as compound nouns, abbreviations, and acronyms. We address this problem by proposing a method to perform schema label normalization which increases the number of comparable labels. The method semi-automatically expands abbreviations/acronyms and annotates compound nouns, with minimal manual effort. We empirically prove that our normalization method helps in the identification of similarities among schema elements of different data sources, thus improving schema matching results
Normalización de texto en español de Argentina
Tesis (Lic. en Cs. de la Computación)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía, Física y Computación, 2018.En la actualidad la cantidad de datos que consume y genera una sola persona es gigantesca. Los datos cada vez son más, ya que cualquiera puede generarlos. Esto trae consigo un aumento en el ruido que hay en esos datos. Es por eso que el texto de las redes sociales se caracteriza por ser ruidoso, lo que es un problema cuando se quiere trabajar sobre ellos. En este trabajo construimos un corpus de tweets en español de Argentina. Recolectamos un conjunto grande de tweets y luego los seleccionamos manualmente para obtener una muestra representativa de los errores típicos de normalización. Luego, definimos criterios claros y explícitos de corrección y los utilizamos para proceder a la anotación manual del corpus. Además, presentamos un sistema de normalización de texto que trabaja sobre tweets. Dado un conjunto de tweets como entrada, el sistema detecta y corrige las palabras que deben ser estandarizadas. Para ello, utiliza una serie de componentes como recursos léxicos, sistemas de reglas y modelos de lenguaje. Finalmente, realizamos experimentos con diferentes corpus, entre ellos el nuestro, y diferentes configuraciones del sistema para entender las ventajas y desventajas de cada uno.Nowadays, the amount of data consumed and generated by only one person is enormous. Data amount keeps growing because anyone can
generate it. This brings along an increment of noisy data. That is why social network text is noisy, which is a problem when it is needed to work on it.
Here, we built a corpus of tweets in argentinian spanish. We collected a big set of tweets and we selected them manually to obtain a representative sample of common normalization errors. Then, we defined explicit and clear correction criteria and we used it to continue with the manual corpus annotation.
Besides, we present a text normalization system that works on tweets.
Given a set of tweets as input, the system detects and corrects words that need to be standardized. To do that, it uses a group of components as
lexical resources, rule-based systems and language models.
Finally, we made some experiments with different corpus, among them, the one we built, and different system configurations to understand each one’s advantages and disadvantages
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Deciphering clinical text: concept recognition in primary care text notes
Electronic patient records, containing data about the health and care of a patient, are a valuable source of information for longitudinal clinical studies. The General Practice Research Database (GPRD) has collected patient records from UK primary care practices since the late 1980s. These records contain both structured data (in the form of codes and numeric values) and free text notes. While the structured data have been used extensively in clinical studies, there are significant practical obstacles in extracting information from the free text notes. The main obstacles are data access restrictions, due to the presence of sensitive information, and the specific language of medical practitioners, which renders standard language processing tools ineffective.
The aim of this research is to investigate approaches for computer analysis of free text notes. The research involved designing a primary care text corpus (the Harvey Corpus) annotated with syntactic chunks and clinically-relevant semantic entities, developing a statistical chunking model, and devising a novel method for applying machine learning for entity recognition based on chunk annotation. The tools produced would facilitate reliable information extraction from primary care patient records, needed for the development of clinically-related research. The three medical concept types targeted in this thesis could contribute to epidemiological studies by enhancing the detection of co-morbidities, and better analysing the descriptions of patient experiences and treatments.
The main contributions of the research reported in this thesis are: guidelines for chunk and concept annotation of clinical text, an approach to maximising agreement between human annotators, the Harvey Corpus, a method for using a standard part-of-speech tagging model in clinical text chunking, and a novel approach to recognising clinically relevant medical concepts
Sentiment Classification of Online Customer Reviews and Blogs Using Sentence-level Lexical Based Semantic Orientation Method
ABSTRACT
Sentiment analysis is the process of extracting knowledge from the peoples‟ opinions, appraisals and emotions toward entities, events and their attributes. These opinions
greatly impact on customers to ease their choices regarding online shopping, choosing events, products and entities. With the rapid growth of online resources, a vast amount
of new data in the form of customer reviews and opinions are being generated progressively. Hence, sentiment analysis methods are desirable for developing
efficient and effective analyses and classification of customer reviews, blogs and
comments.
The main inspiration for this thesis is to develop high performance domain
independent sentiment classification method. This study focuses on sentiment analysis
at the sentence level using lexical based method for different type data such as
reviews and blogs. The proposed method is based on general lexicons i.e. WordNet,
SentiWordNet and user defined lexical dictionaries for sentiment orientation. The
relations and glosses of these dictionaries provide solution to the domain portability problem. The experiments are performed on various data sets such as customer reviews and blogs comments. The results show that the proposed method with sentence contextual information is effective for sentiment classification. The proposed method performs better than word and text level corpus based machine learning methods for semantic orientation. The results highlight that the proposed method achieves an average accuracy of 86% at sentence-level and 97% at feedback level for customer reviews. Similarly, it achieves an average accuracy of 83% at sentence level and 86% at
feedback level for blog comment
Dealing with spelling variation in Early Modern English texts
Early English Books Online contains facsimiles of virtually every English work printed between 1473 and 1700; some 125,000 publications. In September 2009, the Text Creation Partnership released the second instalment of transcriptions of the EEBO collection, bringing the total number of transcribed works to 25,000. It has been estimated that this transcribed portion contains 1 billion words of running text. With such large datasets and the increasing variety of historical corpora available from the Early Modern English period, the opportunities for historial corpus linguistic research have never been greater. However, it has been observed in prior research, and quantified on a large-scale for the first time in this thesis, that texts from this period contain significant amounts of spelling variation until the eventual standardisation of orthography in the 18th century. The problems caused by this historical spelling variation are the focus of this thesis. It will be shown that the high levels of spelling variation found have a significant impact on the accuracy of two widely used automatic corpus linguistic methods - Part-of-Speech annotation and key word analysis. The development of historical spelling normalisation methods which can alleviate these issues will then be presented. Methods will be based on techniques used in modern spellchecking, with various analyses of Early Modern English spelling variation dictating how the techniques are applied. With the methods combined into a single procedure, automatic normalisation can be performed on an entire corpus of any size. Evaluation of the normalisation performance shows that after training, 62% of required normalisations are made, with a precision rate of 95%
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